Auxiliary wheel side braking system and engineering machinery

Abstract

The utility model relates to an auxiliary wheel-side braking system for engineering machinery with a hydrostatic driving dry-type bridge, which comprises a brake pump, an oil inlet of which is in fluid connection with a hydraulic oil tank; the brake oil cylinder is constructed to be used for receiving hydraulic oil from the brake pump so as to apply wheel side braking force to the brake caliper; an oil inlet of the brake valve group is in fluid connection with an oil outlet of the brake pump, a working oil port of the brake valve group is in fluid connection with the brake oil cylinder, and the brake valve group is provided with a first working position where the oil inlet is communicated with the working oil port. The auxiliary wheel side braking system further comprises a braking energy accumulator arranged between an oil outlet of the braking pump and an oil inlet of the braking valve set. The brake energy accumulator is configured to receive hydraulic oil from the brake pump for energy storage and provide the hydraulic oil for the brake oil cylinder through the brake valve set only when the engineering machine goes downhill, the brake valve set is located at the first working position and the engine fails. The utility model further relates to engineering machinery with the system.

Description

Technical Field

[0001] The utility model relates to the technical field of brake systems, in particular to an auxiliary wheel brake system for an engineering machinery with a hydrostatic drive dry bridge and an engineering machinery comprising the auxiliary wheel brake system. Background Art

[0002] Hydrostatic engineering machinery usually adopts hydrostatic drive technology, using hydraulic oil as the medium. The hydraulic pump draws the oil from the oil tank and controls the flow through the control valve to enter the hydraulic motor to rotate it, thereby driving the driven components to work. Hydrostatic engineering machinery typically includes hydrostatic drive rollers. For rollers using hydrostatic drive dry bridges, the following working conditions may occur: when going downhill, if one side of the tire is vacant, due to the existence of the dry bridge differential, the roller still cannot brake normally after driving and parking brakes. Even if the traditional auxiliary wheel side brake system is enabled, when the engine is turned off or the engine fails, the auxiliary wheel side brake system loses its braking force, and the braking demand cannot be met, which poses a danger to the entire machine and the driver on board.

[0003] Therefore, the present invention is dedicated to one or more improvements to the prior art. Utility Model Content

[0004] In view of the defects of the prior art, the utility model proposes an improved technology for the auxiliary wheel-side braking system of engineering machinery with a hydrostatic drive dry axle. This improved technology enables the wheel-side braking system to still function as an emergency brake even after the engine fails during downhill driving, thereby meeting braking needs and improving the problem of brake failure.

[0005] According to one aspect of the utility model, an auxiliary wheel brake system for an engineering machinery with a hydrostatic drive dry bridge is provided, comprising:

[0006] a brake pump, wherein an oil inlet of the brake pump is fluidically connected to a hydraulic oil tank;

[0007] A brake cylinder configured to receive hydraulic oil from the brake pump to apply wheel braking force to a brake caliper disposed on the drive axle;

[0008] A brake valve group, wherein the oil inlet of the brake valve group is fluidly connected to the oil outlet of the brake pump, the working oil port of the brake valve group is fluidly connected to the brake cylinder, and has a first working position and a second working position. In the first working position, the oil inlet of the brake valve group is communicated with the working oil port, and in the second working position, the oil inlet of the brake valve group is communicated with the oil return port.

[0009] It is characterized in that the brake pump is driven by an engine, and the auxiliary wheel-side braking system also includes a brake accumulator arranged between the oil outlet of the brake pump and the oil inlet of the brake valve group, and the brake accumulator is constructed to receive hydraulic oil from the brake pump for energy storage and only provide hydraulic oil to the brake cylinder through the brake valve group when the engineering machinery is downhill, the brake valve group is in the first working position and the engine fails.

[0010] Advantageously, the brake valve group includes a solenoid valve having a first port connected to the oil inlet of the brake valve group, a second port connected to the working oil port of the brake valve group, a third port and a fourth port connected to the oil return port of the brake valve group, wherein when the solenoid valve is powered off, the first port and the second port are fluidically connected, the third port and the fourth port are fluidically connected, and the brake valve group is in a first working position; when the solenoid valve is powered on, the first port and the fourth port are fluidically connected, the second port and the third port are fluidically connected, and the brake valve group is in a second working position.

[0011] Advantageously, the brake valve group further comprises a one-way valve, an oil inlet of the one-way valve is fluidically connected to the fourth port of the solenoid valve, and an oil outlet of the one-way valve is fluidically connected to the hydraulic oil tank.

[0012] Advantageously, the brake valve group further comprises a relief valve, an oil inlet of the relief valve is fluidically connected to the first port of the solenoid valve, and an oil outlet of the relief valve is fluidically connected to the third port of the solenoid valve.

[0013] Advantageously, the brake valve assembly further comprises a filter arranged between the brake accumulator and the first port of the solenoid valve.

[0014] Advantageously, the brake valve assembly is configured as a single valve block integrating the solenoid valve, the non-return valve, the overflow valve and the filter.

[0015] Advantageously, the solenoid valve is electrically connected to an emergency stop switch of the engineering machinery, and the solenoid valve is de-energized when the emergency stop switch is pressed.

[0016] According to another aspect of the present invention, there is provided an engineering machine, characterized in that the engineering machine comprises the above-mentioned auxiliary wheel side braking system.

[0017] Advantageously, the construction machine is a road roller or a loader.

[0018] According to the utility model, the auxiliary wheel side braking system is additionally provided with a brake accumulator, which can ensure automatic emergency braking even in a downhill period, when one side of the tire is vacant and the engine fails at the same time, and can meet a sufficient number of braking operations to improve the safety of the machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Exemplary embodiments of the present invention are described with reference to the accompanying drawings, in which:

[0020] Figure 1 The utility model is a schematic diagram of an auxiliary wheel side brake system for an engineering machinery with a hydrostatic drive dry bridge.

[0021] Reference numerals

[0022] 1- auxiliary wheel side brake system; 10- brake pump; 12- brake cylinder; 13- brake valve group; 130- solenoid valve; 131- first port; 132- second port; 133- third port; 134- fourth port; P- oil inlet; A- working oil port; T1- first oil return port; T2- second oil return port; 16- one-way valve; 17- overflow valve; 18- filter; 15- filtering device; 11- hydraulic oil tank.

[0023] The accompanying drawings are only schematic and not necessarily drawn to scale, and they only show those parts necessary to illustrate the utility model, and other parts are omitted or only mentioned. That is, in addition to the parts shown in the accompanying drawings, the utility model may also include other parts. DETAILED DESCRIPTION

[0024] The technical solution of the utility model is described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth so that the technical personnel in the relevant technical field can more fully understand the utility model. However, it is obvious to the technical personnel in the relevant technical field that the implementation of the utility model may not have some of these specific details. In addition, it should be understood that the utility model is not limited to the specific embodiments introduced. On the contrary, it can be considered to implement the utility model with any combination of the following features and elements, whether or not they relate to different embodiments.

[0025] Figure 1 The auxiliary wheel brake system 1 for an engineering machine with a hydrostatically driven dry bridge of the present invention is shown. The auxiliary wheel brake system of the present invention is described below using a hydrostatically driven dry bridge roller as an example, but it can be understood that the same inventive principle can be applied to any other applicable engineering machine or other types of vehicles.

[0026] like Figure 1As shown, the auxiliary wheel brake system 1 includes a brake pump 10, a brake cylinder 12, a brake valve group 13 and a brake accumulator 14. The oil inlet of the brake pump is fluidly connected to the hydraulic oil tank 11, and the oil outlet is fluidly connected to the brake cylinder 12 through the brake valve group 13. The hydraulic oil from the brake pump 10 enters the brake cylinder, pushes the piston to move, and then applies a force to the brake caliper provided on the driving axle of the roller, thereby providing wheel braking force. In the advantageous embodiment shown in the figure, the brake pump 10 is driven by an engine (not shown).

[0027] exist Figure 1 In the illustrated embodiment, the brake valve assembly 13 includes a solenoid valve 130 , and may also advantageously include a one-way valve 16 , a relief valve 17 and a filter 18 .

[0028] The solenoid valve 130 may be configured as a two-position four-way valve, which has a first port 131, a second port 132, a third port 133 and a fourth port 134, wherein the first port 131 is fluidly connected to the oil outlet of the brake pump 10, the second port 132 is fluidly connected to the brake cylinder 12, the third port 133 is fluidly connected to the hydraulic oil tank 11, and the fourth port 134 is fluidly connected to the oil inlet of the one-way valve 16. The oil outlet of the one-way valve 16 is fluidly connected to the oil return oil circuit leading to the hydraulic oil tank.

[0029] When the solenoid valve 130 is de-energized, the solenoid valve 130 is in the first working position ( Figure 1 In this case, the first port 131 and the second port 132 are in fluid communication, and the third port 133 and the fourth port 134 are in fluid communication. In this way, the hydraulic oil from the brake pump 10 is supplied to the brake cylinder 12 via the brake valve group 13, so that the brake cylinder enters the braking state and thus provides wheel side braking force.

[0030] When the solenoid valve 130 is energized, the solenoid valve 130 is in the second working position ( Figure 1 In this case, the first port 131 is in fluid communication with the fourth port 134, and the second port 132 is in fluid communication with the third port 133. In this way, the hydraulic oil from the brake pump 10 flows into the return oil pipeline via the brake valve group 13. The hydraulic oil in the brake cylinder will be discharged into the hydraulic oil tank via the brake valve group 13, and the braking state of the whole machine will be released. A filter device 15 is provided on the return oil pipeline to filter the hydraulic oil in the pipeline before it flows into the hydraulic oil tank 11.

[0031] Due to the presence of the one-way valve 16 , when the solenoid valve 130 is in the second working position, the hydraulic oil discharged from the brake valve group 13 will not flow to the brake pump but only flow to the hydraulic oil tank 11 .

[0032] The solenoid valve 130 is electrically connected to the emergency stop switch (not shown) of the roller. When the emergency stop switch is pressed, the solenoid valve 130 is de-energized, the solenoid valve switches from the second working position to the first working position, and the brake pump 10 supplies oil to the brake cylinder 12, so that the brake caliper enters the braking state and provides wheel side braking force. The emergency stop switch can be set in the cab of the roller so that it can be manually operated by the driver.

[0033] The oil inlet of the relief valve 17 is fluidically connected to the first port 131 of the solenoid valve 130, and the oil outlet of the relief valve 17 is fluidically connected to the hydraulic oil tank 11. Through the relief valve 17, the maximum hydraulic pressure (e.g., 10 MPa) that can be supplied to the brake cylinder can be set, and thus the maximum braking force that the brake cylinder 12 can provide can be set.

[0034] The filter 18 may be disposed between the oil outlet of the brake pump 10 and the first port 131 of the solenoid valve 130 to ensure cleanliness of the hydraulic oil so as to prevent the solenoid valve 130 from being stuck.

[0035] like Figure 1 As shown, the solenoid valve 130, the one-way valve 16, the relief valve 17 and the filter 18 can be integrated in one valve block, whereby the brake valve group 13 can be constructed as an integral valve group or valve block. The first port 131 of the solenoid valve 130 is fluidly connected to the oil inlet P of the brake valve group, the second port 132 of the solenoid valve 130 is fluidly connected to the working oil port A of the brake valve group 13, the third port 133 of the solenoid valve 130 is fluidly connected to the first oil return port T1 of the brake valve group 13, and the fourth port 134 of the solenoid valve 130 is fluidly connected to the second oil return port T2 of the brake valve group 13. Therefore, when the solenoid valve 130 is in the first working position, the brake valve group is also in the first working position in which the oil inlet P is connected to the working oil port A. When the solenoid valve is in the second working position, the brake valve group is also in the second working position in which both the oil inlet P and the working oil port A are connected to the oil return port.

[0036] exist Figure 1 In the illustrated embodiment, the brake accumulator 14 is disposed between the oil inlet P of the brake valve group 13 and the oil outlet of the brake pump 10. The brake accumulator 14 is configured to store energy using the hydraulic oil from the brake pump 10, and is configured to provide hydraulic oil to the brake cylinder 12 via the brake valve group 13 only when the construction machine is traveling downhill, the brake valve group is in the first working position, and the engine fails.

[0037] Combine the following Figure 1 The working principle of the auxiliary wheel side braking system of the utility model is explained.

[0038] In the normal working state of the roller, the whole machine is powered on, the solenoid valve 130 in the brake valve group 13 is powered, and the solenoid valve 130 is in the second working position ( Figure 1The brake accumulator 14 works in the right position. At this time, part of the hydraulic oil from the brake pump 10 fills the brake accumulator 14 to store energy. The other part of the hydraulic oil from the brake pump flows into the hydraulic oil tank 11 after passing through the brake valve group (i.e., the flow channel connecting the first port and the fourth port of the solenoid valve). The filling process of the brake accumulator 14 reaches a predetermined level and the filling is stopped. At this time, the hydraulic oil from the brake cylinder 12 flows into the hydraulic oil tank 11 through the brake valve group (i.e., the flow channel connecting the second port and the third port of the solenoid valve) to unload the oil. In this way, incomplete brake release is prevented and the braking state of the entire machine is released. At this time, the service brake of the roller is completed by static hydraulic drive.

[0039] When the roller is on a downhill section and one side of the tire is free, due to the structure of the dry bridge, the normal service brake and parking brake can no longer meet the braking needs of the roller, and the driver needs to press the emergency stop switch of the roller. When the driver presses the emergency stop switch, the solenoid valve 130 in the brake valve group 13 is de-energized, and the solenoid valve 130 switches from the second working position to the first working position ( Figure 1 The left position in the middle). The hydraulic oil provided by the brake pump 10 will reach the brake cylinder 12 through the brake valve group 13 to provide wheel-side braking force. If the engine fails suddenly at this time (for example, an unexpected malfunction or flameout), the brake pump 10 cannot provide brake oil. At this time, the pressure difference between the internal energy storage pressure of the brake accumulator 14 and the oil inlet of the brake valve group drives the brake accumulator opening to open, and the hydraulic oil flows from the brake accumulator to the brake valve group 13. At this time, the brake valve group 13 is in the first working position, and the hydraulic oil provides hydraulic oil to the brake cylinder 12 through the brake valve group 13 for braking. The overflow valve 17 ensures the maximum oil pressure flowing into the brake cylinder. The brake accumulator 14 is constructed so that its internal energy storage pressure can ensure that the roller can still perform such braking twice after the engine is turned off.

[0040] Therefore, the utility model solves the problem of the roller being unable to brake under specific working conditions (i.e., downhill section, one-side tire is empty and engine failure) in the prior art at low cost and with high reliability by adding a brake accumulator in the auxiliary wheel side braking system and applying corresponding control through the brake valve group, and can meet multiple braking needs and improve the problem of brake failure of the roller.

[0041] Industrial Applicability

[0042] According to the utility model, the hydrostatic drive dry bridge roller has a brake accumulator added to the auxiliary wheel side brake system, which advantageously allows the brake accumulator to store energy during the normal working period of the roller. When a tire on one side is vacant on a downhill section, the brake accumulator is automatically opened in response to engine failure (failure or flameout) to supply brake oil to the brake cylinder, so that the emergency and dangerous situation can be responded to in time without the need for additional reaction operations by the driver. The storage pressure of the brake accumulator can be designed to ensure that at least two such emergency brakes are completed to improve the safety of the machine.

[0043] In addition, the entire auxiliary wheel brake system has a simple structure and is flexible and convenient to control. Therefore, the auxiliary wheel brake system according to the utility model is suitable for a wide range of applications.

[0044] The auxiliary wheel brake system according to the utility model can be used in engineering machinery such as a road roller or a loader to achieve desired work and operation, and is also applicable to other machinery with similar working conditions.

[0045] The above exemplary embodiments have made a clear and complete description of the utility model. It should be understood by those skilled in the art that various other embodiments can be conceived by modifying the disclosed technical solutions without departing from the spirit and scope of the utility model. These embodiments should be understood to fall within the scope of the utility model determined based on the claims and any equivalent technical solutions thereof.

Claims

1. An auxiliary wheel brake system, which is used for an engineering machine with a hydrostatic drive dry bridge, comprising: a brake pump, wherein an oil inlet of the brake pump is fluidically connected to a hydraulic oil tank; A brake cylinder configured to receive hydraulic oil from the brake pump to apply wheel braking force to a brake caliper disposed on the drive axle; A brake valve group, wherein the oil inlet of the brake valve group is fluidly connected to the oil outlet of the brake pump, the working oil port of the brake valve group is fluidly connected to the brake cylinder, and has a first working position and a second working position. In the first working position, the oil inlet of the brake valve group is communicated with the working oil port, and in the second working position, the oil inlet of the brake valve group is communicated with the oil return port. It is characterized in that the brake pump is driven by an engine, and the auxiliary wheel-side braking system also includes a brake accumulator arranged between the oil outlet of the brake pump and the oil inlet of the brake valve group, and the brake accumulator is constructed to receive hydraulic oil from the brake pump for energy storage and only provide hydraulic oil to the brake cylinder through the brake valve group when the engineering machinery is downhill, the brake valve group is in the first working position and the engine fails.

2. The auxiliary wheel side braking system according to claim 1, characterized in that: The brake valve group includes a solenoid valve, which has a first port connected to the oil inlet of the brake valve group, a second port connected to the working oil port of the brake valve group, and a third port and a fourth port connected to the oil return port of the brake valve group, wherein when the solenoid valve is powered off, the first port and the second port are fluidically connected, the third port and the fourth port are fluidically connected, and the brake valve group is in a first working position; when the solenoid valve is powered on, the first port and the fourth port are fluidically connected, the second port and the third port are fluidically connected, and the brake valve group is in a second working position.

3. The auxiliary wheel side braking system according to claim 2, characterized in that: The brake valve group further comprises a one-way valve, an oil inlet of the one-way valve is fluidically connected to the fourth port of the solenoid valve, and an oil outlet of the one-way valve is fluidically connected to the hydraulic oil tank.

4. The auxiliary wheel brake system according to claim 3, characterized in that: The brake valve group further includes a relief valve, an oil inlet of the relief valve is fluidly connected to the first port of the solenoid valve, and an oil outlet of the relief valve is fluidly connected to the third port of the solenoid valve.

5. The auxiliary wheel brake system according to claim 4, characterized in that: The brake valve group further includes a filter disposed between a brake accumulator and the first port of the solenoid valve.

6. The auxiliary wheel brake system according to claim 5, characterized in that: The brake valve group is configured as a single valve block in which the solenoid valve, the check valve, the overflow valve, and the filter are integrated.

7. The auxiliary wheel brake system according to claim 6, characterized in that: The solenoid valve is electrically connected to the emergency stop switch of the engineering machinery, and the solenoid valve is powered off when the emergency stop switch is pressed.

8. An engineering machine, characterized in that: The engineering machinery comprises an auxiliary wheel brake system according to any one of claims 1-7.

9. The construction machine according to claim 8, characterized in that: The engineering machinery is a road roller or a loader.

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